Locomotive-boiler.



Patented Nov. 20, |900.

.1. T. GUNNELLY.

LOGUNIUTIVE BUILEB.

(Application led Oct. 5, 1899.)

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Uwirnn STATES A'rnNT Frias.

JAMES THOMAS OONNELLY, OF MILTON, PENNSYLVANIA.

LoCoMoTIvE-BOILEl-i.

sPEcIFIcATIoN forming para of Letters Patent No. 662,250, dated November 2o, 190e.

Application filed October 5,1899.

T0 all whom, #may concern:

Be it known that I, JAMES THOMAS CON- NELLY, a citizen of the United States, residing at Milton, in the State of Pennsylvania, have invented certain new and useful Improvements in Locomotive-Boilers; and I do hereby declare that the following is a full, clear, and exact description of the invention, which will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to locomotive-boilers; and it has for its object to provide a simple and improved boiler specifically designed for railway-locomotives and which will effectively prevent the tube-heads from bulging under pressure, obviate leaking of the tubes, provide a strong truss or brace within the tube portion and between the back and front tubeheads, materially increase the heating-surface, and consequently the steam-generating power, and which will furthermore possess advantages in point of economy, strength, durability, convenience, power, effectiveness, and general efficiency.

In locomotive boilers as now ordinarily constructed much trouble and expense are experienced in keeping the tubes from leaking, the tubes being the only means for retaining the tube-heads in straight or proper position when under steam-pressure. This trouble has particularly increased in connection with the present use of what is known as the consolidation type of locomotive, which has a steam-pressure as high as two hundred and twenty five pounds. The steam pressure forces the heads away from the tubes, causing the heads to bulge outward, and the diiiculty of leaky tubes is thus 'experienced in all the types of locomotive-boilers now generally in use.

It is the purpose of my present invention and improvements to entirely obviate the dii'iculties above noted, and to this end my invention comprises a combustion-chamberextending longitudinally through the tube portion from the tire-box to the smoke-box, which provides a truss or brace between the back and front tube-heads and which operates to efectually prevent the tube-heads from bulging under pressure and retains the tube-heads and tubes always in proper normal relative position, so that the tubes can- Serial No. 73 2,643. (No model.)

not leak, substantially as hereinafter fully described. Another advantage arising from said longitudinal combustion-chamber and brace is as follows: It is conceded in the art that a square foot of tire-box surface for heating is worth several feet of tube-surface, the reason for which is the difference in teinperature, it being understood that the tirebox takes the larger percentage of heat from the products of combustion and that there is therefore less heat for the tubes to take up. Consequently the tube-surface cannot so effectively operate to generate steam as can the tire-box surface. In practical operation my improved longitudinal combustion-chamber is designed to have a heating power nearly the equivalent of the power of a corresponding square-feet-surface area of the fire-box, this being attained by reason of the fact that the longitudinal combustion-chamber enables an unbroken or unobstructed body of tire extending from the back end of there-box to the front end of said combustion-chamber at the smoke-box. The steam-generating power of my improved locomotive-boiler will thus be great-ly enhanced.

In vthe drawings, Figure l is a longitudinal vertical sectional view of a locomotive-boiler embodying my improvements. Fig. 2 is a transverse vertical sectional view of the same, taken on the line 2 2, Fig. l, and looking forwardly. Fig. 31s a transverse vertical sectional view of the same, taken on the line 3 3, Fig. l, and looking backwardly. Fig. 4 is a transverse vertical sectional View taken on the line 4 4:, Fig. 1.

Corresponding parts in all the figures are denoted by the same letters of reference.

Referring to the drawings, A designates the shell, B the fire-box, O the smoke box or arch, D and E the back and front tube-heads, respectively, and F the tubes extending between said heads, all of which parts may be in the main of any suitable or preferred construction or type. Y

G designates a longitudinal combustionchamber which extends from the fire-box to the smoke-box. This longitudinal combustion-chamber is preferably arranged horizontally and centrally with relation to the set of tubes, as shown, so that it is surrounded by said set or series of tubes. It is prefer- IOO ably of circular contour in cross-section and forms a contin nous tubular combustion-chamber, providing a direct fire-chamber extending between the tire-box and smoke-box. The ends g and g of the longitudinal combustionchamber respectively meet corresponding openings d and d in the back tube-head D and the front tube-head E.

To provide for a truss and brace function of the tubular combustionchamber G between the tube-heads to prevent bulging of the latter under pressure, the ends of said chamber enter corresponding annular flanges h and h', surrounding and projecting laterally from the openings g and g' in the back and front tube-heads, respectively, to which flanges they are bolted, as at t', or otherwise suitably secured.

The front end of the chamber G is preferably of tapering or conical form, as shown at 7c, to avoid too much draft.

I do not of course restrict myself to any specific relative size or dimensions of the respective parts; but in practice, for instance, the tubes F may be two and one-fourth inchesin diameter and the body and back end opening of the longitudinal combustion-chamber G twelve inches in diameter, while its contracted front end opening is eight inches in diameter, it being particularly intended that the longitudinal combustion-chamber be relatively so large that it will provide a great area of heating-surface.

lt will be understood that my improvements are adapted for use in connection with any and all types of railway-locomotive boilers as nowgenerally constructed, such as the straight-top type of shell, as shown in the accompanying designs, or the extended wagon-top shell, and my invention is particularly adapted for the consolidation type of high-pressure locomotive-boilers.

The longitudinal combustion-chamber Gr forms virtually a front extension or continuation of the fire-box, which extension leads through the tube portion to and has its front end terminating at the smoke-box.

The operation and advantages of my invention and improvements will be readily understood by those skilled in the art to which they v appertain. The longitudinal combustionchamber provides a truss or brace to prevent bulging of the tube-heads, a continuous passage for an extended body of fire running from the back of the tire-box to the smokebox, and a great area of heating-surface, thus insuring strength, economy, and eiciency with simplicity of construction.

I do not desire to limit myself to the precise details of construction and arrangement as herein shown and described, as variations and modifications may obviously be made without departing from the spirit and scope of my invention. I therefore reserve the right to all such variations and modifications as properly fall Within the scope of my improvements and the terms of the following claims.

Having thus described my invention, I claim and desire to secure by Letters Patent- l. An improved locomotive-boiler, embodying the fire-box and smoke-box and set of tubes extending between the same, and a longitudinal unobstructed combustion-chamber extending from the fire-box to the smoke-boli` and provided with a relatively-contracted portion whereby a draft reduction is attained, said combustion chamber being arranged within the tube portion and surrounded by the set of tubes, substantially as and for the purpose set forth. l

2. In an improved locomotive-boiler having the fire-box'and smoke-box and set of tubesextending between the same, a longitudinal unobstructed combustion -chamber extending from the fire-box to the smoke-box and having a contracted front end, said chamber being arranged within the tube portion and surrounded by said set of tubes, substantially as and for the purpose set forth.

In testimony whereof I aiiix my signature in presence ol two witnesses.

JAMES THOMAS CONN ELLY.

Witnesses:

HORACE GAUGER, J. F. GAUGER. 

